1. Field of the Invention
The interface between male and female coaxial connectors requires good contact of the outer shield in order to both pass the RF signals with integrity as well as to not allow outside signals to penetrate the cable. This is solved in a variety of ways with RF coaxial connectors. One method used on such connectors as a BNC is to spring-load the grounding components of male and female side. Another method uses threaded male female interfaces requiring precise tightening to set torque levels to insure proper operation. It has been found to maintain the required RF performance that this threaded method requires both a high level of installation craft sensitivity as well as an environment that will not allow loosening over time due to vibration or temperature changes. The F type coaxial connector is used on consumer available applications where it cannot be assured the user will attempt to meet the tightening requirement. There is thus a need for a screw F-Type male connector that will insure electrical continuity despite a loosened male connector nut.
The F-Type male coaxial connectors typically use an inside-threaded front nut to connect a male F-Type connector with a mating outside-threaded female F-Type connector. When tight, the connector maintains a good coaxial cable outer ground/shield connection with the male connector's ferrule tube/post, outer body, and the female F-Type connector shaft. If the male nut is not fully tightened to the female connector, the ground connection between the cable and the connected device may be intermittent. Current methods to remedy this problem of a loose nut is to apply a spring behind the front tube face to spring the F male inner front tube face against the end face of the female. This method has prior art in the BNC and other spring loaded coaxial connectors. This behind-the-front post spring method has a disadvantage if the cable becomes off-axis due to a loose nut since the expected plane-to-plane interface is skewed and may limit conductivity.
2. Description of the Related Art
FIGS. 2-3 show prior art coaxial cable connectors where springs and lock washers are used behind the ferrule-post face to keep the face connected to a female F-Type connector face. FIG. 1 shows a different approach which has a continuity spring forward of the front ferrule face with its contact point facing radially inward against the female body but enclosed in a tube extended from the forward part of the ferrule post. (See U.S. Pat. No. 7,938,680 (the “'680” patent) which is incorporated herein in its entirety and for all purposes).
In the '680 patent, the approach to resolving the electrical continuity problem without the disadvantage of the spring loaded design extends a sleeve attached to the posts' forward end where an inward connection spring is located. This would electrically connect the spring to the tube via contact with the outer sleeve. The disadvantage to this approach is the need for an expensive, very large outer nut to contain the new internal sleeve. In addition, the F connector tightening tools and industry specifications generally require a standard hex nut with an 11 mm hex-hex dimension which is not possible with this inner sleeve design.